The present invention relates to machines for counting small articles and more particularly to a cassette and counter system for tablets and capsules, allowing convenient access to numerous different drugs.
Valuable time is used by pharmacists in the tedious operation of counting out the exact number of tablets or capsules required to fill individual prescriptions. This time could be well utilized by the pharmacist in filling out the label or instructions for the user, in receiving telephone prescriptions from a physician, or in performing many of the other activities that can only be done by a registered pharmacist. The high volume of prescriptions now being filled by pharmacists makes it desirable to provide a means for accurately counting out the required number of tablets or capsules for each particular prescription. Furthermore, some drug items may be purchased in bulk quantity which are then counted into groups and packaged in smaller containers for resale.
The prior art reveals a number of counting machines designed to count a predetermined number of pills or tablets, some of which deposit the respective pills or tablets in a separate container, which are also conveyed by the counting device. Some of the prior art machines are intended for the use of manufacturers where the articles are packaged in large quantity for bulk distribution rather than by the use of an individual pharmacist in filling a prescription for a relatively small number of pills or tablets.
The most pertinent of the prior art patents are U.S. Pat. No. 3,368,713, issued on Feb. 13, 1968, for Article Counting Device and U.S. Pat. No. 4,111,332, issued on Sep. 5, 1978, for Article Counting Device. The subject matter of Pat. No. 4,111,332 relating to the disks for segregating the pills for counting and the machine controls are incorporated herein by reference.
These patents employed a spring arm and a microswitch to detect the pills so as to overcome the problem with light sources and detectors. These problems stemmed from ambient light and dirt and dust on the windows. The use of spring arm and switch detectors however introduced several problems. First, and of considerable importance, are the space requirements of the system. Since the spring arm must be precisely located relative to the article to be dispersed, a separate detector had to be used for every tablet or capsule and thus a separate counting head was required for each different pill. In such systems as many as 6 to 200 different heads are employed. In these locations such as large hospitals, the need for quick delivery of large numbers of different pills renders the systems economical but smaller institutions and smaller drug stores cannot readily afford the cost and space of such systems.
The present invention is an improvement over the above-named patents and other prior article counting and delivery systems for use in smaller institutions and stores by significantly reducing the amount of space and equipment needed to dispense the same variety of drugs and the cost thereof also. Further the improved design prevents any tendency of a springy or spring loaded counter arm to ever bind or bend. Furthermore, if the counter arm is bent, it can scrape on the side of the slot in which it operates and fail to reset fast enough to count the next pill. If this happens an uncounted pill can pass through the exit opening thereby resulting in an inaccurate count. The unique count detector of the present invention eliminates inaccurate counts of this nature.
Further it has been found that microswitch sensors used as pill count detectors in prior devices are susceptible to erroneous readings if one attempts to detect different pills with one device. Mechanical detectors do not provide the necessary versatility to detect a wide variety of shapes or sizes of pills and thus a separate motor driven head with detector is used for each type of tablet or capsule. Further detection difficulties are created by irregular or non-standard shaped drugs. The detector of the present invention eliminates these problems and allows for articles of all shapes and sizes to be detected by a single detector.
Prior Pat. No. 4,111,332 has also suggested the use of other mechanical switches or photoelectric sensing devices. Photoelectric sensors, as indicated above, are sensitive to ambient light, dirt and dust, unlike the detector of the present invention.
Many of the prior art counting machines, but not those of the patents discussed above, provide a single hopper which must be emptied and refilled with the tablets or capsules to be counted and various controls must be set to accommodate the passage of various size capsules or tablets. Further as in the patents discussed above, the use of a separate hopper for each individual group of tablets or capsules along with drive means and counting circuitry for each hopper as presently practiced and is too expensive for all but the highest quantity users. The present invention eliminates the need for refilling and resizing along with eliminating the need for multiple drive means and counting circuitry.